The invention relates to the fish processing art and more particularly to fish processing apparatus which automatically control fish processing operations (e.g., beheading, gutting, splitting, filleting and bone removing operations) in response to measured fish length and fish specie input.
Economical fish processing requires cutting fish at appropriate anatomical locations to minimize waste and avoid subsequent separating operations of unwanted fish parts. Manual fish splitting by skilled artisans is labor intensive and thus not cost effective. Furthermore, as more of the older generation who have the skill for splitting fish retire, fewer fishermen are available who have the skill or willingness to split fish.
As a result, methods for automatically cutting fish were developed. However, automatically controlled fish cutting apparatus must account for various fish sizes within a given specie to enable appropriate processing such as providing for appropriately located cuts.
Methods for automatically controlling cutting tools during fish splitting, gutting and beheading operations according to fish length have incorporated the proportionality principle disclosed in Canadian Fisheries and Aquatic Sciences Report #1457, by J. M. McGlade and E. G. Boulding, "The Truss: A Geometric and Statistical Approach to the Analysis of Form in Fishes" (1986). According to the report, fish of one specie are proportionally identical regardless of length. However, such proportions change among species. For instance, a cod fish might have its anus at a distance from one end of the fish corresponding to 50% of its overall length. On the other hand, a haddock might have similar anatomy at a distance from a similar end corresponding to 45% of its overall length.
Canadian Patent No. 1,050,627 discloses an automatic fish processing apparatus incorporating the above principal in a complex mechanical linkage mechanism which provides proportional control to the cutting tools.
Canadian Patent No. 1,111,313 (Hartman) also incorporates the proportionality principle to control the timing and displacement of the cutting tools. Hartman first determines fish length by counting electrical pulses while the fish is conveyed past a pulse receiver. These pulses are processed by a computer to determine fish length. This value is compared with pre-programmed fish proportionality data to control the cutting tools.